The Memphis/Shelby County EMArecently revised its Help OK placards to be used during an emergency.
The placards, red on one side and labeled Help and green on the other with OK, should be placed in the window with the appropriate side facing out of your home after a large-scale disaster. Shelby County has printed enough for every household in the county and is in the process of distributing the 500,000 posters.
Maybe EMA officials have been eating at Texas de Brazil, because that sounds an awful lot like the red and green discs that the restaurant uses to let waiters know when diners need more meat.